Numerous types of liquid dispensers have been known in the art. Many have been wall-mountable wherein the dispenser serves as a support for a liquid reservoir. Flow of liquid from the reservoir may be by gravity or a combination of gravity and mechanical force. Liquid is used herein broadly to include flowable material such as colloidal mixtures, and pastes.
Dispensers utilizing gravity in combination with mechanical force have had two major problems. The first being obtaining an effective seal across the opening of the liquid reservoir to prevent leakage, and the second being rather complex mechanical and specially configured reservoirs such as illustrated in U.S. Pat. Nos. 4,256,242; 4,258,865; and 4,349,133. These dispensers are not readily adapted to the dispensing of various liquids through wide viscosity ranges.
Thus, the art has a need for a liquid dispenser which can be readily adapted to dispensing liquids of various viscosities and a dispenser which provides for the positive seal of the liquid reservoir to prevent leakage. The present invention can be adapted to dispense liquids having a wide range of viscosities.